Skin Care Goods and Production Method Thereof

ABSTRACT

An object of the present invention is to prove a skin care goods that is low irritant to the skin and superior in wiping efficiency of the dirt in the sulucus cutis and pores of the skin. Thus, the present invention provides a skin care goods of a pile fabric, the pile fabric comprising pile yarns of nanofibers of thermoplastic polymer having a number-average monofilament fineness of 1×10 −8  to 2.2×10 −3  dtex and ground yarns.

TECHNICAL FIELD

The present invention relates to a skin care goods utilizing nanofiber.The term “skin care” used in the present invention is to make the entireskin of the body clean and refreshed, and the “skin care goods” is agoods generally used for that purpose.

BACKGROUND ART

It is very important to remove wastes such as cosmetics and sebumeffectively during face wash for preservation and promotion of skinhealth and for prevention, for example, of acne and pimple. However, itis quite difficult to remove the wastes present in the depth of thewrinkles and pores of the skin simply by normal face wash. In addition,although “waterproof cosmetic preparations” and “waterproof sunscreens”,which were developed along with the recent progress of productiontechnology, have advantages in durability and effectiveness, they alsohave a problem in removal during face wash and cleansing. There are manycleansing lotions developed for removal of these cosmetic preparations,but it is still practically difficult even now to remove the cosmeticpreparations and sebum stains in the pores even with an cleansing oilthat is regarded most effective in cleansing action. In addition, thereare recently in the market many cosmetic preparations that are appliednot only on the face but also on the entire body, especially on the legsand the breast for attractiveness, and these products too have the sameproblem.

On the other hand, generally known is use of a skin care goods employingultrafine fiber, for example partially during face wash, as a means ofincreasing cleaning efficiency.

For example, a skin care goods employing an ultrafine fiber having afineness of 0.001 to 1 dtex is disclosed (e.g., Patent Document 1).

However, the cleansing effect thereof is based on the fine foamsgenerated by a soap solution passing through the fine spaces among theultrafine fibers (see, e.g., Patent Document 1, paragraph number 0020),and the goods is still insufficient in removing highly persistentcosmetic preparation and others completely.

Also disclosed is a skin care goods that wipes off dirt and old cuticledirectly with an ultrafine fiber having a fineness of 0.001 to 1 dtex(e.g., Patent Documents 2 and 3). However, such a method of wiping offdirt and old horny layer by rubbing the skin directly with an ultrafinefiber having a fineness of 0.001 to 1 dtex imposes excessive stimulusand friction on the skin, causing concern about possibly skin troublessuch as chromatosis, cuticle thickening, as well as frictionalmelanoderma in some cases.

As described above, there is still no skin care goods that is lowirritative to the skin and superior in wiping efficiency of the dirt inthe depth of the pores, and thus, there is an urgent need currently forprompt development thereof.

Patent Document 1: Japanese Unexamined Patent Publication No.2004-332149

Patent Document 2: Japanese Unexamined Patent Publication No.2004-329628

Patent Document 3: Japanese Registered Utility Model No. 3100954

Patent Document 4: Japanese Unexamined Patent Publication No.2005-330637

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

An object of the present invention, which was made under thecircumstances above to solve the problems above in traditionaltechnology, is to prove a skin care goods that is low irritant to theskin and superior in wiping efficiency of the dirt in the sulcus cutisand pores of the skin.

Means to Solve the Problems

The present invention, which solved the problems above, has thefollowing aspects:

1. A skin care goods of a pile fabric, the pile fabric comprising pileyarns of nanofibers of thermoplastic polymer having a number-averagemonofilament fineness of 1×10⁻⁸ to 2.2×10⁻³ dtex and ground yarns.2. The skin care goods according to Aspect 1, wherein the thermoplasticpolymer is nylon.3. The skin care goods according to Aspect 1 or 2, wherein thenumber-average monofilament fineness of the nanofiber is 4×10⁻⁴ dtex orless.4. The skin care goods according to any one of Aspects 1 to 3, whereinthe pile yarn is a bundle of nanofiber filaments.5. The skin care goods according to any one of Aspects 1 to 4, whereinthe monofilament fineness of the ground yarn is larger than 8×10⁻⁴ dtex.6. The skin care goods according to any one of aspects 1 to 5, whereinthe monofilament fineness of the ground yarn is larger than 1×10⁻¹ dtex.7. The skin care goods according to any one of Aspects 1 to 6, whereinthe length of the pile is in the range of 1 to 10 mm.8. The skin care goods according to any one of Aspects 1 to 7, whereinthe length of the pile is in the range of 2 to 5 mm.9. The skin care goods according to any one of Claims 1 to 8, whereinthe tips of the pile filaments are cut.10. The skin care goods according to any one of Aspects 1 to 9, whereinthe skin care goods has a sheet shape and the double faced piles.11. The skin care goods according to Aspect 10, wherein the pile fabricswith the single faced piles are laminated to each other.12. A method of producing the skin care goods according to any one ofAspects 1 to 11, comprising a step of forming a nanofiber having anumber-average monofilament fineness of 1×10⁻⁸ to 2.2×10⁻³ dtex bytreating a pile fabric having pile yarns of polymer alloy fibersconsisting of sea and island components with a liquid dissolving the seacomponent but not dissolving the ground yarn.

ADVANTAGEOUS EFFECT OF THE INVENTION

As will be described below, it is possible according to the presentinvention to provide a skin care goods that is superior in the wipingefficiency of removing dirt on the skin surface and also in the depth ofthe sulcus cutis and pores of the skin and yet low irritant to the skin.In addition, the skin care goods utilizing nanofiber according to thepresent invention also provides the user with comfortableness. The skincare goods according to the present invention is also superior indimensional stability and texture and favorable in hand, compared to thefabrics only of nanofiber.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view illustrating an example ofthe woven or knitted fabric constituting the skin care goods accordingto the present invention.

FIG. 2 is a TEM micrograph showing the cross section of a polymer alloyfiber, nanofiber precursor.

FIG. 3 is SEM micrograph showing the surface of a bundle of nylon 6nanofiber filaments.

FIG. 4 is a surface SEM micrograph showing a bundle of nylon 6 nanofiberfilaments when wetted and swollen with water.

FIG. 5 is a cross-sectional micrograph of a pile yarn of a bundle ofnylon 6 nanofiber filaments bonded to an artificial skin (cow leather).

FIG. 6 is a SEM micrograph showing a pile yarn of a bundle of nylon 6nanofiber filaments capturing dirt (a captured dirt particle shown incircle).

FIG. 7 is a schematic view illustrating a bundle of nanofiber filamentsbeing swollen by absorption of water and deformed by external force andcapturing and removing a dirt in the depth of a pore while enclosing thedirt.

FIG. 8 is a schematic view comparing the cut pile (a) and the loop pile(b) of a pile yarn of a bundle of nanofiber filaments.

EXPLANATION OF NUMERALS

-   1: Loop pile yarn-   2: Ground yarn-   3: Cut pile yarn-   4: Cow leather-   5: Nanofiber pile yarn-   6: Nanofiber bundle under standard condition-   7: Nanofiber bundle under wet condition-   8: Nanofiber bundle during deformation-   9: Skin-   10: Dirt particle-   11: Pile fabric ground (basic structure)-   12: Island (domain)-   13: Sea (matrix)

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The thermoplastic polymer for the nanofibers constituting the pile yarnfor the skin care goods according to the present invention may be, forexample, polyester, polyamide, polyolefin, polyphenylene sulfide (PPS)or the like. Among them, polyamides such as nylon 6, which have stronghydrogen bonds, are preferable for preservation of the nanofiber bundleshape, as will be described below.

It is important that the pile yarn is made of nanofibers in the skincare goods according to the present invention. The nanofiber, when used,reaches into the depth of the sulcus cutis and pores of the skin andallows removal of the dirt therein, differently from skin care goodsmade of conventional ultrafine fibers (microfibers). It is probablybecause the nanofiber has a smaller fiber diameter, and also a smallgeometrical moment of inertia, an indicator of the deformability ofnanofiber, of 1.0×10⁻³² to 2.5×10⁻³, which is smaller than that ofconventional ultrafine fibers, and thus, higher fiber flexibility. Thus,the pile yarn, which contains nanofiber filaments that are moredeformable and dispersible when in contact with the skin, reachestogether densely into the depth of sulcus cutis and pores of the skin,removing fine dirt therein (see FIG. 5).

In addition, the nanofiber prohibits localized concentration of stressand also of friction on the skin significantly and enlargement of thepores.

Further, the nanofiber also allows preparation of fine foams having adiameter of 1×10¹ μm or less and adsorption of the dirt in the depth ofthe pores on the fine foams. The foam is smaller and more fine than thatmade with conventional ultrafine fibers reported for example in PatentDocument 3 described above.

On the other hand, with a conventional ultrafine fiber, it is notpossible to make a sufficient number of the filaments fit into thesulcus cutis and pores of the skin, because of its larger monofilamentfineness. Because such a fiber does not give a bundle as described belowand is thus resistant to deformation along the sulcus cutis and pores ofthe skin, it cannot remove the fine dirt therein. In addition, the lessdeforming ultrafine fiber often causes stress concentration on the skin,damaging the horny layer and applying excessive friction on the skin.

The fineness of the nanofiber is 1×10⁻⁸ to 2.2×10⁻³ dtex, asnumber-average monofilament fineness (corresponding to a monofilamentdiameter of 1 to 500 nm in the case of nylon 6), and preferably 4×10⁻⁴dtex or less (corresponding to a monofilament diameter of 211 nm, in thecase of nylon 6 having a density of 1.14 g/cm³), more preferably 2×10⁻⁴dtex or less (monofilament diameter of 149 nm or less in the case ofnylon 6), still more preferably 1×10⁻⁴ dtex or less (monofilamentdiameter of 106 nm or less in the case of nylon 6), and still morepreferably, 8×10⁻⁶ to 6×10⁻⁵ dtex (monofilament diameter of 30 to 82 nmin the case of nylon 6). It is possible advantageously to make thenanofiber fit into the depth of the sulcus cutis and pores of the skineasily and remove the dirt therein, by reducing the number-averagemonofilament fineness of the nanofiber to 2.2×10⁻³ dtex or less. On theother hand, when the fineness is smaller than 1×10⁻⁸ dtex, the nanofiberand also its pile yarn become unsatisfactory in strength.

The nanofiber preferably forms a bundle of filaments by aggregationunder standard condition. The nanofiber bundle swells by absorption ofliquid (see FIG. 4) and is flattened when in contact with the skin, withthe surface nanofiber filaments deforming or dispersing themselves alongthe wrinklessulcus cutis and pores of the skin. The deformation anddispersion of the nanofiber filaments leads to breakdown of larger dirtand takes the dirt deep into the nanofiber bundle. Fine dirt present inthe sulcus cutis and pores of the skin are collected deep into thebundle during high contact of the dispersed nanofiber filaments with thedepth the sulcus cutis and pores of the skin (see FIGS. 6 and 7). Theremoved dirt is protected from re-deposition on the skin, as it is takendeep into the nanofiber bundle.

Such a nanofiber is obtained, for example, by the following method:

Namely, it is produced by preparing a polymer alloy consisting of thesea (matrix) of an easily soluble polymer and islands (domains) of ahardly soluble polymer by using two or more polymers different insolubility in solvents, and spinning and solidifying the polymer alloyinto fiber by cooling. After drawing and heat treatment as needed, thepolymer alloy fiber obtained is treated with a solvent for removal ofthe easily soluble polymer preferably to an extent of 99.9% or more, togive nanofiber.

In the method above, the diameter of the nanofiber is determined mostlyby the size of the islands (domains) in the nanofiber precursor polymeralloy fiber.

The size of the island (domain) may be controlled by adjustment ofpolymer blending, and intense blending in a kneading extruder, staticmixer or the like is desirable.

The combination of polymers also exerts significant influence on thesize of the island (domain). The island (domain) polymer and the sea(matrix) polymer are preferably incompatible to each other, to make theisland (domain) more circular in shape. However, it is difficult todisperse the island (domain) polymer ultrafinely simply by using acombination of different incompatible polymers. Thus, the polymercombination is preferably selected by using solubility parameter (SPvalue) as an indicator. The SP value is a parameter reflecting thecohesive force of substance, which is defined by (energy ofvaporization/molar volume)^(1/2). A difference of two polymer SP valuesof 1 to 9 (MJ/m³)^(1/2) is favorable both for the circularity of theisland (domain) and ultrafine dispersion of the islands byincompatibilization. For example, nylon 6 (N6) and polyethyleneterephthalate (PET), which have a SP value difference of about 6(MJ/m³)^(1/2), is a favorable combination, but N6 and polyethylene (PE),which have a SP value difference of about 11 (MJ/m³)^(1/2), is anexample of unfavorable combination.

The melt viscosity also influenced on the size of the island (domain).It is favorable to make the melt viscosity of the island-componentpolymer smaller than that of the sea-component polymer for production ofnanofiber, because it facilitates deformation of the island-componentpolymer by shearing force and thus fine dispersion of theisland-component polymer. However, excessive reduction of the viscosityof the island-component polymer makes the polymer more like thesea-component polymer, prohibiting increase in the blend rate in theentire fiber, and thus, the viscosity of the island-component polymer ispreferably 1/10 or more of the viscosity of the sea-component polymer.

The solvent dissolving the sea (matrix) polymer but hardly dissolvingthe island (domain) polymer is, for example, an alkaline solution, anacidic solution, an organic solvent, a supercritical fluid, or the like.For example, in the case of a combination of nylon and polyester, Nylonis hardly soluble, while polyester, easily soluble in alkaline solution.

The raw material for the ground yarn constituting the pile fabric in theskin care goods according to the present invention may be a synthetic ora natural fiber, but, if the polymer alloy fiber is converted into thepile yarn by sea-removing treatment after a pile fabrics is prepared,the raw material is preferably a material undissolved in thesea-removing treatment, more preferably the same as the nanofiber usedas pile, from the points of freedom in designing for example of dyeingand also of the texture and touch feeling during use of the resultinggoods.

In addition, the water- or oil-absorbing property thereof is preferablyis not larger than that of the nanofiber for the pile yarn. It is thuspossible to make the nanofiber pile filaments used as the skin-wipinglayer hold aqueous or oil cleansing lotion or facial wash moreefficiently.

The monofilament fineness of the ground yarn is preferably more than8×10⁻⁴ dtex, more preferably 1×10⁻¹ dtex or more. It is possible toimprove the dimensional stability and the texture without sacrifice ofthe nanofiber wiping efficiency, by using such a ground yarn.

Favorable shapes of the pile fabric include woven and knit fabrics.Typical examples of the knit fabrics include circular knitted fabric,tricot fabric, double raschel fabric, and the like.

The length of the pile in pile fabric is preferably in the range of 1 to10 mm, more preferably in the range of 2 to 5 mm. It is possible to makethe nanofiber pile filaments more flexible and provide the filamentswith favorable wiping efficiency and comfortable texture when wet, bymaking the length 1 mm or more. It is also possible to preventdeterioration in texture by fall down of the pile filaments, by makingthe length not more than 10 mm.

The nanofiber pile filaments in the pile fabric of the skin care goodsaccording to the present invention are favorably cut pile. In this way,it is possible to increase the degree of freedom in movement of thenanofiber in pile yarn, to make the tip of the nanofiber fit into thesulcus cutis and pores of the skin, and to increase the wipingefficiency of the yarn. It is further possible to spread the stressapplied to the skin widely during wiping and obtain comfortable textureunder wet condition. (see FIG. 8).

When a conventional microfibers is used for the pile yarn, the cut pileoften gave unfavorable irritate to the skin by contact of the tip of thefiber to the skin. For that reason, the cut of pile filaments at the tipin skin care goods could be conceivable only when such a nanofiber isused.

The possible shapes of the skin care goods according to the presentinvention include towel, mitten, gloves, finger cot, and the like. Thetowel shape is preferable, because it allows modification of its usemethod according to the preference of the user. In addition, shapescovering the hand or the finger such as mitten, gloves and finger cotare also favorable, from the point of easiness in handling.

In addition, double faced pile fabrics a favorable shape of the skincare goods according to the present invention. It is possible, by doublefaced pile fabric containing nanofiber pile yarns, to make the user usethe skin care goods according to the present invention withoutrecognition of the front or rear face of it and improve the handlingefficiency and the impression of use. In processing into such a shape,the pile filaments may be formed directly on both faces of the pilefabric, but, for preparation of a skin care goods with high piledensity, it is preferable to laminated two single faced pile fabrics.For example, a method of sewing the edge of the fabric or a method ofbonding the pile fabrics with an adhesive agent such as urethaneadhesive may be used in laminating the pile fabrics.

Alternatively, a medium such as net that accelerates foaming of facialwash may be used in combination for more favorable foaming of the facialwash.

Yet alternatively, a cushion material covered with a pile fabriccontaining nanofiber pile yarns is also favorable, and the shape thereofmay be mitten or gloves.

Then, the method of producing a skin care goods according to the presentinvention is a method of producing the skin care goods according to thepresent invention, comprising a step of treating a pile fabric havingpile yarns of polymer alloy fibers consisting of sea and islandcomponents with a liquid dissolving the sea component but not dissolvingthe ground yarn and forming nanofiber filaments having a number-averagemonofilament fineness of 1×10⁻⁸ to 2.2×10⁻³ dtex. As described above,the method of subjecting a polymer alloy fiber to a sea-removingtreatment is favorable for forming nanofiber filaments, and it ispossible to obtain good form stability and comfortable texture of a pilefabrics even after sea-component removal, by carrying out thesea-removing treatment with a liquid dissolving the sea component butnot dissolving the ground yarn, i.e., by using a ground yarn resistantto solubilization in the sea-removing treatment.

EXAMPLES Measuring Method (1) Weight-Average Molecular Weight ofPolylactic Acid

A sample was dissolved in chloroform, and tetrahydrofuran was addedthereto, to give a test solution. It was analyzed by using agel-permeation chromatographic (GPC) apparatus Waters 2690 manufacturedby Waters at 25° C. to give weight-average molecular weight aspolystyrene.

(2) Number-Average Monofilament Fineness of Nanofiber

Five pile filaments were withdrawn at random from a region of 5 cm×5 cmin dimension, and each ultrathin section thereof in the filamentcross-sectional direction was prepared and observed under a transmissionelectron microscope (TEM) (H-7100FA, manufactured by Hitachi Ltd.,magnification: 100,000).

From the TEM micrograph of the fiber cross-sectional section by usingimage processing software (WINROOF) the monofilament diameters of 300 ormore filaments chosen at random in the same cross section respectivelyof the five pile yarns, i.e., a total of 1,500 cross sections, weredetermined, and the simple average thereof obtained was used as thenumber-average monofilament diameter of the nanofiber. A monofilamentfineness was calculated from the monofilament diameter according to thefollowing Formula:

Number-average monofilament fineness(dtex)=(d×D ²×π/4)×10⁻⁸

Wherein, d: density (g/cm³), and D: number-average monofilament diameter(nm).

(3) Evaluation of Dirt-Wiping Efficiency A

The artificial skin used for evaluation was an expanded polyethylenesheet (“Toraypef”®, manufactured by Toray Industries, Inc.). A highlywaterproof cosmetic preparation (eye liner fluid, manufactured byShiseido Co., Ltd.) was applied thereon in a circular shape of 1 cm indiameter and dried at 20±2° C. and 65±2% RH for 12 hours.

The test piece was cut into a piece of 6 cm in length and 8 cm in width;a cleansing lotion (white cleansing water, manufactured by KoseCosmeport Corp.) was impregnated into the test piece in an amount of 2.6times of the mass of the test piece; and the test piece was bonded to asilicone rubber plate (6 cm in length×7 cm in width×1 cm in thickness).

The artificial skin in the area coated with the cosmetic preparation wasrubbed for wiping reciprocally five times with the test piece under aloaded pressure of 0.5 cN/mm² (300 g/2.5 cm²), a velocity of 2 cm/s, anda wiping width of 2 cm. Removal of dirt after the wiping operation wasevaluated by visual examination and rated in the following fivecategories.

5: All dirt in the sulcus cutis of artificial skin removed4: Some dirt remaining in the sulcus cutis of artificial skin3: Significant dirt remaining in the sulcus cutis of artificial skin2: Some dirt remaining in the sulcus cutis and also on the surface ofartificial skin1: Significant dirt remaining in the sulcus cutis and also on thesurface of artificial skin

(4) Evaluation of Dirt-Wiping Efficiency B

A highly waterproof cosmetic preparation (eye liner fluid, manufacturedby Shiseido Co., Ltd.) was applied in an area of 0.5 cm×2 cm on theinternal arm and dried thereon under normal temperature and normalhumidity for 30 minutes.

The test piece was cut into a piece of 6 cm in length and 8 cm in width;a cleansing lotion (white cleansing water, manufactured by KoseCosmeport Corp.) was impregnated into the test piece in an amount 2.6times of the mass of the test piece; and the test piece was wound arounda silicone rubber rod (diameter: approximately 8 mm), and the arm areapreviously coated with the cosmetic preparation was wiped ten times in afixed direction.

Removal of dirt after the wiping operation was evaluated under amicroscope (VH-6300C manufactured by Keyence Corp., magnification: 300)and rated in the following five categories.

5: All dirt in the depth of the sulcus cutis and pores of the skinremoved4: Some dirt remaining in the depth of the sulcus cutis and pores of theskin3: Significant dirt remaining in the depth of the sulcus cutis and poresof the skin2: Some dirt remaining in the depth of the sulcus cutis and pores andalso on the surface of the skin1: Significant dirt remaining in the depth of the sulcus cutis and poresand also on the surface of the skin

(5) Irritation Test

An agar sheet prepared by dissolving agar (pure agar, manufactured bySanada Co., Ltd.) and solidifying the solution by cooling was used asthe artificial skin for evaluation.

The test piece was cut into a piece of 6 cm in length and 8 cm in width;water was impregnated into the sheet in an amount of 2.6 times of themass of the test piece; the test piece was wound around a siliconerubber rod (diameter: approximately 8 mm), and the surface of the agarsheet was wiped ten times in a fixed direction.

The scratching on the agar sheet surface after wiping operation wasobserved by visual examination and rated in the following fivecategories.

5: No scratching of the surface of the agar4: Some scratching of the surface of the agar3: scratching of the surface of the agar2: Deep scratching of the surface of the agar1: Many deep scratchings of the surface of the agar

(6) Evaluation of Foaming Efficiency

A polyethylene net of 10 cm×10 cm in dimension (8 mesh) was used as themedium accelerating foaming, and the net was enclosed tightly with thetest piece of 15 cm×15 cm, and the opening was sewn with a cotton yarn.

A face wash solution (concentration: 20 mass %, temperature 37° C.) wasimpregnated therein in an amount of 30% of the mass of the test piece,and the test piece was beaten a hundred times with a pestle for foaming.The surface shape of the foam obtained was observed under a microscope(VH-6300 C manufactured by Keyence Corp., magnification: 300 times).

(7) Monitoring Test (Face Wash Puff Application)

The test piece was cut into a piece of 6 cm in length and 8 cm in width,and a cleansing lotion (white cleansing water, manufactured by KoseCosmeport Corp.) was impregnated into the test piece in an amount of 2.6times of the test piece mass. A makeup cleansing test by using the testpiece was carried out with 50 females in 20's to 50's of age, and theefficiency of removal of cosmetic preparation, texture, skin irritation,convenience in use, and others were studied by questionnaire survey.

(8) Monitoring Test (Facial Washcloth Application)

The test piece was cut into a piece of 6 cm in length and 8 cm in width;and the test piece was then wetted with a facial wash (“Dove® moisturefoam F” manufactured by Unilever Japan Co., Ltd.) and then allowed tofoam.

A monitoring test by using the test piece was carried out with 50females in 20's to 50's of age, and the efficiency of removal ofcosmetic preparation, texture, skin irritation, convenience in use, andothers were studied by questionnaire survey.

Example 1 Polymer Alloy Fiber

Nylon 6 (N6) having a melt viscosity 212 Pa·s (262° C., at a shear rateof 121.6 sec⁻¹) and a melting point of 220° C. (45 mass %) andpoly-L-lactic acid having a weight-average molecular weight of 120,000,a melt viscosity of 30 Pa·s (240° C., shear rate: 2432 sec⁻¹), a meltingpoint of 170° C., and an optical purity of 99.5% or more (55 mass %)were weighed separately, and fed separately to a biaxial extrusionkneader described below in detail, where they are melted and blended at220° C., to give polymer alloy chips.

Screw shape: Unidirectional complete-gearing double-start thread screwScrew diameter: 37 mm,Effective length: 1670 mm, L/D=45.1Blending region length: extrusion side from ⅓ of screw effective lengthVent: 2 positions.

The polymer alloy chip obtained was supplied to a spinning machine,molten at 230° C. therein, filtered through a metal nonwoven fabrichaving a critical filtration diameter of 15 μm in the spin block at aspinning temperature of 230° C., and melt-spun out of nozzles having adiameter of 0.3 mm and a length of 0.55 mm at a nozzle plate temperature215° C. The extruded filaments were solidified by cooling in the rangeof 1 m in length with cooling air at 20° C., applied with an oil by anoil supply guide placed 1.8 m below the nozzles, withdrawn at a spinningrate of 3000 m/minute, and then, drawn under the condition of a drawingtemperature of 90° C. at a drawing rate of 1.5 and a heat settemperature of 130° C.

The multifilament of polymer alloy fiber thus obtained had a size of 133dtex/48 filaments, a strength of 3.6 cN/dtex, an elongation of 40%, anda Percentage Uster of 0.7%. Observation of the cross-sectional sectionof the polymer alloy fiber obtained under TEM revealed that it had asea/island structure containing poly-L-lactic acid as the sea (matrix)and N6 as islands (domains) and the islands (domains) were dispersedvery finely at a number-average diameter of 110 nm.

(Pile Yarn)

The multifilament of the polymer alloy fiber was used as the pile yarn.

(Ground Yarn)

A nylon 6 multifilament having a total fineness of 75 dtex of 24filaments (monofilament fineness: 3.1 dtex) was used as the ground yarn.

(Knitting)

A loop-pile knitted fabric having a pile length of 2.2 mm was preparedin a sinker-pile single circular knitting machine by using themultifilament of the polymer alloy fibers as the pile yarn and also asthe ground yarn.

(Skin Caregoods)

The pile knitted fabric was treated with 1% aqueous sodium hydroxidesolution at a temperature of 98° C. and a bath ratio of 1:100 for 1 hourby immersion, removing 99.9% or more of the polylactic acid in thepolymer alloy fiber by hydrolysis, and thus, giving a skin care goods ofa pile fabric having pile yarns of N6 nanofiber bundles and ground yarnsof N6 multifilaments.

The fineness distribution of the N6 nanofiber, as determined from the1,500 samples in measurement (1), was in the range of 1×10⁻⁸ to 4×10⁻⁴dtex, and the number-average monofilament fineness thereof was 1×10⁻⁴dtex.

The skin care goods obtained gave favorable results both in thedirt-wiping efficiency tests A and B. In the irritation test, the skincare goods was extremely low irritative. It also gave favorable resultsin all test items in the monitoring test. In addition in the foamingefficiency test, generation of fine foams having a diameter of 10 μm orless was observed.

Example 2 Polymer Alloy Fiber

A multifilament of polymer alloy fiber similar to that in Example 1 wasprepared.

(Pile Yarn)

The multifilament of polymer alloy fiber above was used as the pileyarn.

(Ground Yarn)

The yarn the same as that used in Example 1 was used as the ground yarn.

(Knitting)

A pile knitted fabric was prepared in a similar manner to Example 1 byusing the pile yarn and the ground yarn.

(Skin Care Goods)

The pile knitted fabric was subjected to sea-removing treatment in asimilar manner to Example 1 and the tip of the loop pile was cut byemery processing, to give a skin care goods.

The skin care goods obtained gave favorable results both in thedirt-wiping efficiency tests A and B. Favorably in the irritation test,there was almost no scratching observed on the surface. It also gavefavorable results in all test items in the monitoring test. Inparticular, there were many opinions that the texture of the goods wasmore favorable in the questionnaire survey, compared to the results inExample 1, because of cut pile. In the foaming efficiency test,generation of fine foams having a diameter of 10 μm or less wasobserved.

Example 3 Polymer Alloy Fiber

A multifilament of polymer alloy fiber similar to that in Example 1 wasprepared.

(Pile Yarn)

The multifilament of polymer alloy fiber was used as the pile yarn.

(Ground Yarn)

A nylon 6 multifilament having a total fineness of 110 dtex of 24filaments (monofilament fineness: 4.6 dtex) was used as the ground yarn.

(Knitting)

A pile knitted fabric was prepared in a similar manner to Example 1,except that the ground yarn above was used.

(Skin Caregoods)

The pile knitted fabric was subjected to sea-removing treatment in asimilar manner to Example 1, to give a skin care goods.

The fineness distribution of the N6 nanofiber, as determined from the1,500 samples in measurement (1), was in the range of 1×10⁻⁸ to 4×10⁻⁴dtex, and the number-average monofilament fineness thereof was 1×10⁻⁴dtex.

The skin care goods obtained gave favorable results both in thedirt-wiping efficiency test A and B. In the irritation test, the skincare goods was extremely low irritative. It also gave favorable resultsin all test items in the monitoring test. In particular, themonofilament of ground yarn was thicker and rigidder than that of theskin care goods prepared in Example 1, and thus, there were manyopinions that the goods was superior in dimensional stability and morefavorable in the convenience in use in the questionnaire survey.Alternatively in the foaming efficiency test, generation of fine foamshaving a diameter of 10 μm or less was observed.

Example 4 Polymer Alloy Fiber

A multifilament of polymer alloy fiber similar to that in Example 1 wasprepared.

(Pile Yarn)

The multifilament of polymer alloy fiber above was used as the pileyarn.

(Ground Yarn)

A nylon 6 multifilament having a total fineness of 110 dtex of 24filaments (monofilament fineness: 4.6 dtex) was used as the ground yarn.

(Knitting)

A pile knitted fabric was prepared in a similar manner to Example 1 byusing the pile yarn and the ground yarn.

(Skin Care Goods)

The pile knitted fabric was subjected to sea-removing treatmentsimilarly to that used in Example 1.

(The Processings Above are the Same as Those in Example 3.)

Then, the tip of the loop pile was cut by emery processing, to give askin care goods.

The skin care goods obtained gave favorable results both in thedirt-wiping efficiency tests A and B. Favorably in the irritation test,there was almost no scratching observed on the surface. It also gavefavorable results in all test items in the monitoring test. Inparticular, because of cut pile, there were many opinions that thetexture was “very comfortable” than in Example 3 in the questionnairesurvey. In particular, the monofilament of ground yarn was thicker andrigidder than that of the skin care goods prepared in Example 2, andthus, there were many opinions that the goods was superior indimensional stability and more favorable in the convenience in use inthe questionnaire survey. Alternatively in the foaming efficiency test,generation of fine foams having a diameter of 10 μm or less wasobserved.

Examples 5 and 6 Polymer Alloy Fiber

A multifilament of polymer alloy fiber similar to that in Example 1 wasprepared.

(Pile Yarn)

The multifilament of polymer alloy fiber above was used as the pileyarn.

(Ground Yarn)

A nylon 6 multifilament having a total fineness of 110 dtex of 24filaments (monofilament fineness: 4.6 dtex) was used as the ground yarn(similarly to Example 3).

(Knitting)

A double raschel fabric having a gap between the two knitted fabrics at6.0 mm was prepared by using the pile and ground yarns in a doubleraschel knitting machine. The double raschel knitted fabric was cut intotwo fabrics in the region corresponding to a pile length of 1:3, to givea cut pile knitted fabric having a pile length of 1.5 mm and a cut pileknitted fabric having a pile length of 4.5 mm.

(Skin Care Goods)

The two kinds of pile knitted fabrics were respectively subjected tosea-removing treatment similarly to that described in Example 1, to giveskin care goods. The goods having a pile length of 1.5 mm was preparedin Example 5, while that having a pile length of 4.5 mm was prepared inExample 6.

Each of the N6 nanofiber used in Examples 5 and 6 had a finenessdistribution, as determined from 1,500 samples in measurement (1), inthe range of 1×10⁻⁸ to 4×10⁻⁴ dtex, and the number-average monofilamentfineness thereof was 1×10⁻⁴ dtex.

Each of the samples obtained showed favorable results both in thedirt-wiping efficiency tests A and B. Favorably in the irritation test,there was almost no scratching observed on the surface in both Examples.Also in the monitoring tests, the samples of both Examples gavefavorable result in all test items. In particular in Example 6, therewere more favorable opinions on texture in the questionnaire survey.Alternatively in the foaming efficiency test, generation of fine foamshaving a diameter of 10 μm or less was observed.

Examples 7 and 8 Polymer Alloy Fiber

A multifilament of polymer alloy fiber similar to that in Example 1 wasprepared.

(Pile Yarn)

The multifilament of polymer alloy fiber above was used as the pileyarn.

(Ground Yarn)

A nylon 6 multifilament having a total fineness of 110 dtex of 24filaments (monofilament fineness: 4.6 dtex) was used as the ground yarn(similarly to Example 3).

(Knitting)

A double raschel fabric having a gap between the two knitted fabrics at6.0 mm was prepared by using the pile and ground yarns in a doubleraschel knitting machine. The double raschel fabric was cut into twofabrics in the region corresponding to a pile length of 5:7, to give acut pile knitted fabric having a pile length of 2.5 mm and a cut pileknitted fabric having a pile length of 3.5 mm.

Both in Examples 7 and 8, the fineness distribution of the N6 nanofiber,as determined from the 1,500 samples in measurement (1), was in therange of 1×10⁻⁸ to 4×10⁻⁴ dtex, and the number-average monofilamentfineness thereof was 1×10⁻⁴ dtex.

(Skin Care Goods)

The two kinds of pile knitted fabrics were respectively subjected tosea-removing treatment similarly to that described in Example 1, to giveskin care goods. The goods having a pile length of 2.5 mm was preparedin Example 7, while that having a pile length of 3.5 mm was prepared inExample 8.

Each of the samples obtained showed favorable results both in thedirt-wiping efficiency tests A and B. Favorably in the irritation test,there was almost no scratching observed on the surface in both Examples.Also in the monitoring test, the samples of both Examples gave favorableresults in all test items. In particular in both Examples, there weremore favorable opinions on texture in the questionnaire survey.Alternatively in the foaming efficiency test, generation of fine foamshaving a diameter of 10 μm or less was observed.

Example 9 Polymer Alloy Fiber

A multifilament of polymer alloy fiber similar to that in Example 1 wasprepared.

(Pile Yarn)

The multifilament of polymer alloy fiber above was used as the pileyarn.

(Ground Yarn)

The yarn identical with that used in Example 1 was used as the groundyarn.

(Knitting)

A pile knitted fabric was prepared in a similar manner to Example 1 byusing the pile and ground yarns.

(Skin Care Goods)

The pile knitted fabric was subjected to sea-removing treatmentsimilarly to that used in Example 1, and then, the tip of the loop pilewas cut by raising in emery processing, to give a skin care goods.

(The Processings Above are the Same as Those in Example 2.)

Two test pieces of the cut pile knitted fabric cut to a dimensionsuitable were prepared respectively, and sewn with a cotton thread withthe ground yarn faces thereof facing each other, to give a skin caregoods with the double faced piles.

The skin care goods obtained gave favorable results both in thedirt-wiping efficiency tests A and B. Favorably in the irritation test,there was almost no scratching observed. It also gave favorable resultsin all test items in the monitoring test. Because two sheets werelaminated, there were many opinions that the goods was superior in handand convenience in use in the questionnaire survey. Alternatively in thefoaming efficiency test, generation of fine foams having a diameter of10 μm or less was observed.

Example 10 Polymer Alloy Fiber

A multifilament of polymer alloy fiber similar to that in Example 1 wasprepared.

(Pile Yarn)

The multifilament of polymer alloy fiber above was used as the pileyarn.

(Ground Yarn)

The yarn identical with that used in Example 1 was used as the groundyarn.

(Knitting)

A pile knitted fabric was prepared in a similar manner to Example 1 byusing the pile and ground yarns.

(Skin Caregoods)

The pile knitted fabric was subjected to sea-removing treatmentsimilarly to that used in Example 1, and then, the tip of the loop pilewas cut by emery processing, to give a skin care goods.

(The Processings Above are the Same as Those in Example 2.)

Two cut pile knitted fabrics obtained were piled on and bonded to eachother with their ground yarn faces facing each other; and the groundyarn faces were bonded to each other with a urethane-based adhesive(Tyforce® 865HV, manufactured by Dainippon Ink and Chemicals, Inc.) inthe dotted pattern in a coating amount of approximately 4 g/m², to givea skin care goods with double faced pile.

The skin care goods obtained gave favorable results both in thedirt-wiping efficiency tests A and B. Favorably in the irritation test,there was almost no scratching observed. It also gave favorable resultsin all test items in the monitoring test. Because two sheets werelaminated, there were many opinions that the goods was superior in handand convenience in use in the questionnaire survey. Alternatively in thefoaming efficiency test, generation of fine foams having a diameter of10 μm or less was observed.

Comparative Example 1

A commercially available microfiber facial washcloth (removal towel,available from Cogit Co., Ltd., number-average monofilament fineness:0.22 dtex) was evaluated.

In the dirt-wiping efficiency test, the washcloth was found to beunsatisfactory both in test items A and B, compared to the skin caredevice according to the present invention. Also in the irritation test,it showed strong scratching action. In addition, it was not foundfavorable compared to the skin care goods according to the presentinvention in each test item of the monitoring test. Further in thefoaming efficiency test, there were observed only large foams having adiameter of about 100 μm to 1 mm.

Comparative Example 2

A commercially available microfiber-based facial washcloth (PreriCuticle-Refreshing Cloth®, manufactured by Lucky Corporation) wasevaluated.

In the dirt-wiping efficiency test, the washcloth was found to beunsatisfactory both in test items A and B, compared to the skin caregoods according to the present invention. Also in the irritation test,it showed strong scratching action. In addition, it was not foundfavorable compared to the skin care goods according to the presentinvention in each test item of the monitoring test. In particular, therewere many opinions that it was more irritant and stimulating to the skinand caused tingle after use. Also in the foaming efficiency test, therewere observed only large foams having a diameter of about 100 μm to 1mm.

Comparative Example 3

A commercially available microfiber-based facial washcloth (Toraysee®facial washcloth, manufactured by Toray Industries, Inc., number-averagemonofilament fineness: 0.08 dtex) was evaluated.

In the foaming efficiency test, there were observed fine foams having adiameter of 1 to 20 μm, and the size of the foams was not even.

TABLE 1 Example 1 Example 2 Example 3 Example 4 Pile length 2.2 mm 2.2mm 2.2 mm 2.2 mm Pile shape Loop Cut Loop Cut Ground yarn 75 × 24 ← 110× 24 ← dtex(dexitex)xf(filament) Configuration Single-sided Single-sidedSingle-sided Single-sided pile cloth pile cloth pile cloth pile clothDirt-wiping effeciency test A 4 5 4 5 Dirt-wiping effeciency test B 4 54 5 Irritation test 4 5 4 5

TABLE 2 Example 5 Example 6 Example 7 Example 8 Pile length 1.5 mm 4.5mm 2.5 mm 3.5 mm Pile shape Cut Cut Cut Cut Ground yarn 110 × 24 ← 110 ×24 ← dtex(dexitex)xf(filament) Configuration Single-sided Single-sidedSingle-sided Single-sided pile cloth pile cloth pile cloth pile clothDirt-wiping effeciency test A 5 5 5 5 Dirt-wiping effeciency test B 5 55 5 Irritation test 4 5 5 5

TABLE 3 Comparative Comparative Comparative Example 9 Example 10 Example1 Example 2 Example 3 Pile length 2.2 mm 2.2 mm — — — Pile shape Cut Cut— — — Ground yarn 75 × 24 ← — — — dtex(dexitex)xf (filament)Configuration Double-sided Double-sided Double-sided — — pile cloth pilecloth pile cloth (2 sheet sewn) (2 sheet sewn) Dirt-wiping 5 5 3 3 2effeciency test A Dirt-wiping 5 5 2 2 3 effeciency test B Irritationtest 5 4 2 1 1

TABLE 4 Example 1 Example 2 Example 3 Example 4 Sample Pile length 2.2mm 2.2 mm 2.2 mm 2.2 mm description Pile shape Loop Cut Loop Cut Groundyarn dtex(dexitex)xf 75 × 24 ← 110 × 24 ← (filament) ConfigurationSingle-sided Single-sided Single-sided Single-sided pile cloth pilecloth pile cloth pile cloth Questionnaire description When used cosmeticvery favorble 33 42 33 40 as face removal Not different 15 6 14 7 washpaff from when only facial wash was used (Apparent) 2 2 3 3 backstaining of the dirt on cloth Texture Very comfortable 32 43 32 42Comfortable 5 3 8 5 Not comfortable 7 2 3 3 Unpleasant 2 0 2 0 Others 41 5 0 Skin None 32 40 33 42 irritation Some 8 2 7 3 Significant 2 0 3 3Others 8 8 7 2 Convenience Very good 20 25 27 30 in use Good 10 13 12 12Fair 18 9 9 6 Bad 2 3 2 2 Very Bad 0 0 0 0 Others 0 0 0 0 Possibility ofYes 33 32 32 42 future use Yes/no 10 10 10 7 No 5 3 3 0 Others 2 5 5 1

TABLE 5 Example 5 Example 6 Example 7 Example 8 Sample Pile length 1.5mm 4.5 mm 2.5 mm 3.5 mm description Pile shape Cut Cut Cut Cut Groundyarn dtex(dexitex)xf 110 × 24 ← 110 × 24 ← (filament) ConfigurationSingle-sided Single-sided Single-sided Single-sided pile cloth pilecloth pile cloth pile cloth Questionnaire description When used cosmeticvery favorble 43 42 45 44 as face removal Not different 7 2 3 3 washpaff from when only facial wash was used (Apparent) 0 6 2 3 backstaining of the dirt on cloth Texture Very comfortable 42 48 48 48Comfortable 5 0 0 0 Not comfortable 2 0 0 0 Unpleasant 1 2 2 2 Others 07 0 0 Skin None 32 48 42 47 irritation Some 7 0 3 0 Significant 3 0 0 0Others 8 2 5 3 Convenience Very good 27 42 38 35 in use Good 8 3 5 3Fair 13 2 2 2 Bad 0 0 2 2 Very Bad 0 0 0 0 Others 2 3 3 8 Possibility ofYes 35 43 42 45 future use Yes/no 10 5 5 3 No 3 2 2 0 Others 2 0 1 2

TABLE 6 Comparative Comparative Comparative Example 9 Example 10 Example1 Example 2 Example 3 Sample Pile length 2.2 mm 2.2 mm — — — descriptionPile shape Cut Cut — — — Ground yarn dtex(dexitex)xf 75 × 24 ← — — —(filament) Configuration Double-sided Double-sided Double-sided — — pilecloth pile cloth pile cloth (2 sheet sewn) (2 sheet sewn) Questionnairedescription When used cosmetic very favorble 43 47 23 23 22 as faceremoval Not different 5 2 15 17 17 wash paff from when only facial washwas used (Apparent) 2 1 12 10 11 back staining of the dirt on clothTexture Very comfortable 44 43 20 12 8 Comfortable 3 2 8 10 10 Notcomfortable 0 0 10 18 22 Unpleasant 0 0 10 8 8 Others 3 5 2 2 2 SkinNone 40 42 17 5 5 irritation Some 3 2 13 15 8 Significant 0 0 18 26 33Others 7 6 2 4 4 Convenience Very good 47 45 30 15 20 in use Good 2 2 710 5 Fair 0 0 3 23 23 Bad 0 0 3 2 2 Very Bad 0 0 2 0 0 Others 1 3 5 0 0Possibility of Yes 45 45 22 10 5 future use Yes/no 3 2 8 17 22 No 0 1520 20 Others 2 3 5 3 3

TABLE 7 Example 1 Example 2 Example 3 Example 4 Sample Pile length 2.2mm 2.2 mm 2.2 mm 2.2 mm description Pile shape Loop Cut Loop Cut Groundyarn dtex(dexitex)xf 75 × 24 ← 110 × 24 — (filament) ConfigurationSingle-sided Single-sided Single-sided Single-sided pile cloth pilecloth pile cloth pile cloth Questionnaire description When used as Dirtremoval Very favorable 34 43 33 43 face wash puff Not different 13 7 147 from when only facial wash was used (Apparent) 3 0 3 0 back stainingof the dirt on cloth Texture Very comfortable 32 47 33 45 Comfortable 50 8 2 Not comfortable 7 2 5 0 Unpleasant 2 1 2 2 Others 4 0 2 1 SkinNone 35 40 37 43 irritation Some 5 2 5 2 Significant 2 0 3 0 Others 8 85 5 Convenience Very good 20 20 30 32 in use Good 10 8 10 15 Fair 15 135 2 Bad 3 3 2 0 Very Bad 2 6 2 1 Others 0 0 1 0 Possibility of Yes 33 3837 42 future use Yes/no 10 7 8 5 No 5 3 3 2 Others 2 2 2 1

TABLE 8 Example 5 Example 6 Example 7 Example 8 Sample Pile length 1.5mm 4.5 mm 2.5 mm 3.5 mm description Pile shape Cut Cut Cut Cut Groundyarn dtex(dexitex)xf 110 × 24 — 110 × 24 — (filament) ConfigurationSingle-sided Single-sided Single-sided Single-sided pile cloth pilecloth pile cloth pile cloth Questionnaire description When used as Dirtremoval Very favorable 45 45 47 45 face wash puff Not different 5 5 2 3from when only facial wash was used (Apparent) 0 0 1 2 back staining ofthe dirt on cloth Texture Very comfortable 43 48 48 48 Comfortable 3 0 00 Not comfortable 2 0 0 0 Unpleasant 2 2 2 2 Others 0 0 0 0 Skin None 3248 42 47 irritation Some 7 0 3 0 Significant 3 0 0 0 Others 8 2 5 3Convenience Very good 33 42 38 35 in use Good 10 3 5 3 Fair 5 2 2 2 Bad0 0 2 2 Very Bad 0 0 0 0 Others 2 3 3 8 Possibility of Yes 35 43 42 45future use Yes/no 10 5 5 3 No 3 2 2 0 Others 2 0 1 2

TABLE 9 Comparative Comparative Comparative Example 9 Example 10 Example1 Example 2 Example 3 Sample Pile length 2.2 mm 2.2 mm — — — descriptionPile shape Cut Cut — — — Ground yarn dtex(dexitex)xf 75 × 24 ← — — —(filament) Configuration Double-sided Double-sided Double-sided — — pilecloth pile cloth pile cloth (2 sheet sewn) (2 sheet sewn) Questionnairedescription When used as Dirt removal Very favorable 43 45 23 18 15 facewash puff Not different 5 3 17 19 20 from when only facial wash was used(Apparent) 2 2 10 13 15 back staining of the dirt on cloth Texture Verycomfortable 44 42 17 13 8 Comfortable 3 7 8 13 12 Not comfortable 3 0 1317 22 Unpleasant 0 0 10 3 3 Others 0 1 2 4 5 Skin None 42 38 17 10 15irritation Some 5 7 15 13 8 Significant 0 0 15 24 17 Others 3 5 3 3 10Convenience Very good 42 40 22 18 15 in use Good 7 7 5 5 5 Fair 0 2 1015 23 Bad 0 0 7 5 2 Very Bad 0 0 3 5 3 Others 1 1 3 2 2 Possibility ofYes 45 43 18 11 12 future use Yes/no 2 3 17 15 17 No 0 2 15 23 20 Others3 2 0 1 1

INDUSTRIAL APPLICABILITY

The skin care goods according to the present invention, which issignificantly less simulative to the skin and superior in the efficiencyof wiping off the dirt in the depth of the pores, is extremely useful inthe field of skin care goods.

1. A skin care goods of a pile fabric, the pile fabric comprising pileyarns of nanofibers of thermoplastic polymer having a number-averagemonofilament fineness of 1×10⁻⁸ to 2.2×10⁻³ dtex and ground yarns. 2.The skin care goods according to claim 1, wherein said thermoplasticpolymer is nylon.
 3. The skin care goods according to claim 1, whereinthe number-average monofilament fineness of said nanofibers is 4×10⁻⁴dtex or less.
 4. The skin care goods according to claim 1, wherein saidpile yarn is a bundle of nanofiber filaments.
 5. The skin care goodsaccording to claim 1, wherein the monofilament fineness of said groundyarns is larger than 8×10⁻⁴ dtex.
 6. The skin care goods according toclaim 1, wherein the monofilament fineness of said ground yarns islarger than 1×10⁻¹ dtex.
 7. The skin care goods according to claim 1,wherein the length of the pile is in the range of 1 to 10 mm.
 8. Theskin care goods according to claim 1, wherein the length of the pile isin the range of 2 to 5 mm.
 9. The skin care goods according to claim 1,wherein the tips of the pile filaments are cut.
 10. The skin care goodsaccording to claim 1, wherein said skin care goods has a sheet shape anddouble faced pile.
 11. The skin care goods according to claim 10,wherein said pile fabrics with the single faced pile are laminated toeach other.
 12. A method of producing the skin care goods according toclaim 1, comprising a step of forming a nanofiber having anumber-average monofilament fineness of 1×10⁻⁸ to 2.2×10⁻³ dtex bytreating a pile fabric having pile yarns of polymer alloy fibersconsisting of sea and island components with a liquid dissolving the seacomponent but not dissolving the ground yarn.